TMI but PLEASE HELP ALL ADVICE WELCOMED.

Why do I have a tiny fluid like sack on the top right above my vagina hole and if I push it light yellow creamy stuff comes out. it's like the gland right above my vagina hole that fills up with this stuff. I can easily push it out. it usually gets big when I masturbate so I feel like it's just a gland filling up. it doesn't hurt at all and its not uncomfortable I just want to know if I should be concerned because getting to a doctor is hard. I'm 17 and yes I'm sexually active.